CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of priority to Korean Patent Application No. 10-2023-0084329 filed on Jun. 29, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND
1. Field

The present subject matter relates to a heat pump and a control method thereof.

2. Description of Related Art

Generally, a heat pump is a device that cools an indoor space during a cooling operation or heats the indoor space during a heating operation, and specifically, in the case of a cooling operation, heat passes through the compressor and is released to the outside in an outdoor heat exchanger installed outside, and an indoor heat exchanger disposed indoors absorbs indoor heat through a pressure reducing means and performs evaporation, thereby cooling the indoor space. In case of a heating operation, a refrigerant evaporated from an outdoor heat exchanger disposed outside is compressed through a compressor, and the compressed high-temperature, high-pressure refrigerant condenses in an indoor heat exchanger disposed indoors and releases heat into the indoor space to heat the indoor space. Here, the outdoor heat exchanger uses an outdoor air heat source to operate as a condenser during cooling operation and as an evaporator during a heating operation.

For this heat pump, specifically, during heating operations in situations in which an outdoor temperature is low, a low-temperature refrigerant flowing through the outdoor heat exchanger may cause frost formation in the outdoor heat exchanger due to insufficient absorption of heat energy outdoors, and furthermore, a problem of reduced heating efficiency may occur due to an insufficient temperature increase of the refrigerant passing through the outdoor heat exchanger. Meanwhile, there is a need to research technologies that may secure both cooling and heating performance in heat pumps.

PRIOR ART REFERENCE
Patent Document

(Patent Document 1) KR10-2004-0052049 A (Jun. 19, 2004)

SUMMARY

In order to solve the aforementioned problem, the aspect of the present invention is to provide a heat pump that may improve cooling performance and heating performance.

In order to achieve the aforementioned purpose, according to an embodiment of the present invention, provided is a heat pump including: a circulation flow path in which a flow direction of a refrigerant is switched depending on a cooling mode or a heating mode; a first outdoor heat exchanger and a second outdoor evaporative heat exchanger arranged in series on the circulation flow path; and a flow path switching valve disposed on the circulation flow path and switching the flow direction of the refrigerant in the circulation flow path so that the refrigerant is evaporated while flowing in the order of the second outdoor evaporative heat exchanger and the first outdoor heat exchanger in the heating mode.

Furthermore, the flow path switching valve may switch the flow direction of the refrigerant in the circulation flow path so that the refrigerant is condensed while flowing in the order of the first outdoor heat exchanger and the second outdoor evaporative heat exchanger in the cooling mode.

In an embodiment, the first outdoor heat exchanger may be comprised of a first outdoor air-cooling type heat exchanger.

Furthermore, the first outdoor air-cooling type heat exchanger may include a tube through which the refrigerant flows and a fin disposed on the tube.

In an embodiment, the first outdoor heat exchanger and the second outdoor evaporative heat exchanger may be disposed adjacently to each other. In this case, the heat pump may include one outdoor fan disposed between the first outdoor heat exchanger and the second outdoor evaporative heat exchanger.

Furthermore, the first outdoor heat exchanger and the second outdoor evaporative heat exchanger may be disposed to be inclined at a certain angle from a vertical direction on the circulation flow path.

The second outdoor evaporative heat exchanger includes a water injection module configured to perform a water injection operation by supplying cooling water toward the second outdoor evaporative heat exchanger in the cooling mode and configured not to perform the water injection operation in the heating mode.

Meanwhile, according to another embodiment of the present invention, provided is a control method of a heat pump including a first outdoor heat exchanger and a second outdoor evaporative heat exchanger arranged in series on a circulation flow path in which a flow direction of a refrigerant is switched depending on a cooling mode or a heating mode, wherein the refrigerant is controlled to be evaporated while flowing in the order of the second outdoor evaporative heat exchanger and the first outdoor heat exchanger in the heating mode.

Furthermore, the refrigerant may be controlled to condense while flowing in the order of the first outdoor heat exchanger and the second outdoor evaporative heat exchanger in the cooling mode.

In an embodiment, the first outdoor heat exchanger may be comprised of an air-cooling type heat exchanger.

Furthermore, the first outdoor heat exchanger and the second outdoor evaporative heat exchanger share one outdoor fan.

Furthermore, the second outdoor evaporative heat exchanger operates as an evaporative condenser by performing a water injection operation in the cooling mode, and operates as an air-cooling type evaporator without the water injection operation in the heating mode.

According to a heat pump having the aforementioned configuration and a control method thereof, in a heating mode, a refrigerant flows in the order of the second outdoor evaporative heat exchanger and the first outdoor heat exchanger, so that frost formation of condensate is induced mainly in the first outdoor heat exchanger, and the evaporation efficiency of the refrigerant of the second outdoor evaporative heat exchanger may be secured to improve heating efficiency, and also, a quick defrosting operation may be performed on the first outdoor heat exchanger. In addition, in a cooling mode, the refrigerant may flow in the order of the first outdoor heat exchanger and the second outdoor evaporative heat exchanger, and the refrigerant may be condensed more efficiently through water injection in the second outdoor evaporative heat exchanger, thereby effectively improving cooling efficiency.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the present invention will be more clearly understood from the detailed following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view illustrating a configuration of a heat pump according to an embodiment of the present invention;

FIG. 2 is an exemplary view illustrating a configuration of an example of a first outdoor heat exchanger in a heat pump according to an embodiment of the present invention;

FIG. 3 is an view exemplary illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 4 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 5 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 6 is a schematic view illustrating an operating process in a heating mode of the heat pump according to an embodiment of the present invention; and

FIG. 7 is a schematic view illustrating an operating process in a cooling mode of a heat pump according to an embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, with reference to the attached drawings, specific example embodiments of the present invention will be described. However, the concept of the present invention is not limited to the suggested embodiments. For example, those skilled in the art who understand the idea of the present invention may easily propose other degenerative inventions or other embodiments included within the scope of the concept of the present invention by adding, modifying, or deleting components in the scope of the same concept, but other degenerative inventions or other embodiments are also construed as being in the scope of the concept of the present invention.

Furthermore, throughout the specification, the terms “connected to” or “coupled to” are used to designate a connection or coupling of one element to another element and include both a case where an element is “directly connected or coupled to” another element and a case where an element is “indirectly connected or coupled to” another element via still another element. Furthermore, when a certain portion “includes” or “comprises” a certain component, this indicates that other components are not excluded and may be further included unless otherwise noted.

In addition, components with the same function within the scope of the same concept illustrated in the drawings of each embodiment will be described using the same reference numerals.

FIG. 1 is a schematic view illustrating a configuration of a heat pump according to an embodiment of the present invention, FIG. 2 is an exemplary view illustrating a configuration of an example of a first outdoor heat exchanger in a heat pump according to an embodiment of the present invention, FIG. 3 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention, FIG. 4 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention, and FIG. 5 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention. FIG. 6 is a schematic view illustrating an operating process in a heating mode of the heat pump according to an embodiment of the present invention, and FIG. 7 is a schematic view illustrating an operating process in a cooling mode of a heat pump according to an embodiment of the present invention.

Referring to FIG. 1, a heat pump 10 according to an embodiment of the present invention may include a circulation flow path 100 in which a flow direction of a refrigerant is switched depending on a cooling mode or a heating mode, an indoor heat exchangers 200 disposed on each of the circulation flow path 100 and exchanging heat with indoor air, a compressor 300 configured to compress the refrigerant, an expansion valve 400 configured to decompresses the refrigerant, a first outdoor heat exchanger 500, a second outdoor evaporative heat exchanger 600, and a flow path switching valve 700 configured to switch the flow direction of the refrigerant in the circulation flow path 100.

The second outdoor evaporative heat exchanger 600 in the present invention may be an evaporative heat exchanger of various shapes, and for example, an evaporative condenser disclosed in published patents such as KR10-2019-0006781, KR 10-2022-0074734, and KR10-2021-0070921 may be used, but the present disclosure is not limited thereto. By utilizing the second outdoor evaporative heat exchanger 600, the cooling performance of the heat pump may be efficiently improved. Here, when the second outdoor evaporative heat exchanger 600 operates as an evaporator in the heating mode, the second outdoor evaporative heat exchanger 600 operates as an air-cooling type evaporator without water injection. In this case, the evaporation efficiency may be insufficient due to the structure of the second outdoor evaporator heat exchanger with a relatively small heat exchange area. Therefore, in order to improve heating efficiency in a heating mode, a structure in which the first outdoor heat exchanger 500 is additionally arranged in series with the second outdoor evaporator heat exchanger on the circulation flow path 100 is applied.

Here, in the heat pump 10, in the cooling mode, the indoor heat exchanger 200 operates as an evaporator, and the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 operate as condensers. Additionally, in the heat pump 10, in the heating mode, the indoor heat exchanger 200 operates as a condenser, and the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 operate as evaporators.

Specifically, when explained based on the heating mode, the heat pump 10 according to an embodiment of the present invention may include a circulation flow path 100, a compressor 300 configured to compress the refrigerant into a high-temperature and high-pressure gaseous refrigerant, an indoor heat exchanger 200 configured to heat the indoor air while allowing a refrigerant passing through the compressor 300 to exchange heat with the indoor air and to be condensed into a medium-temperature and high-pressure liquid refrigerant and an indoor fan F1 blowing the indoor air toward the indoor heat exchanger 200, an expansion valve 400 configured to decompress a refrigerant passing through the indoor heat exchanger 100 into a low-temperature and low-pressure refrigerant, a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 configured to allow a refrigerant passing through the expansion valve 400 to exchange heat with outdoor air and to be evaporated into a low-temperature and low-pressure gaseous refrigerant and an outdoor fan F2 blowing the outdoor air toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600. In other words, the indoor heat exchanger 200, the compressor 300, the expansion valve 400, the first outdoor heat exchanger 500, the second outdoor evaporative heat exchanger 600, and the flow path switching valve 700 may be disposed on the circulation flow path 100.

Additionally, the heat pump 10 according to an embodiment of the present invention may further include a gas-liquid separator 800 disposed on an upstream side of the compressor 300 in a flow direction of the refrigerant in both the cooling mode and the heating mode, and serves to filter a liquid refrigerant from the refrigerant flowing into the compressor 300 by the gas-liquid separator 800. In other words, the gas-liquid separator 800 may be disposed on the circulation flow path 100 connected between the flow path switching valve 700 and the compressor 300 to be described below, so that by changing the flow direction of the refrigerant by the flow path switching valve 700, the gas-liquid separator 800 is disposed on the upstream side of the compressor 300 in both the cooling mode and the heating mode, by which the refrigerant passing through the gas-liquid separator 800 may be allowed to flow into the compressor 300, thereby implementing a filtering effect for the refrigerant.

In the circulation flow path 100, the flow direction of the refrigerant is switched depending on the cooling mode or the heating mode. Specifically, a flow path switching valve 700 to be described below may be disposed in the circulation flow path 100, so that the flow direction of the refrigerant may be switched depending on the cooling mode or the heating mode through the flow path switching valve 700.

The flow path switching valve 700 is a four-way valve and may be disposed on a downstream side of the compressor 300, so that the refrigerant passing through the compressor 300 flows toward the indoor heat exchanger 200 in the heating mode, and the flow path switching valve 700 may switch the flow direction of the refrigerant so that the refrigerant passing through the compressor 300 flows toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 in the cooling mode. That is, in the heating mode, the refrigerant evaporated from the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500, which operate as evaporators may be compressed through the compressor 300, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser while releasing heat into the indoor space, thereby performing heating. Additionally, in the cooling mode, the refrigerant passes through the compressor 300 and releases heat from the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 operating as condensers, and passes through the expansion valve 400 and the indoor heat exchanger 200 operating as an evaporator absorbs indoor heat and performs evaporation, thereby cooling the indoor space.

The first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be arranged in series on the circulation flow path 100.

Here, the first outdoor heat exchanger 500 may be made of various types of heat exchangers. The first outdoor heat exchanger 500 may be formed of a different type of heat exchanger from the second outdoor evaporative heat exchanger 600, and may be formed of first outdoor air-cooling type heat exchangers 500a and 500b. As an example, as illustrated in FIG. 2, the first outdoor air-cooling type heat exchanger 500a may include a tube 510a through which refrigerant flows and a fin 520a disposed on the tube 510a. Here, the tube 510a may have a circular shape, and the fins 520a may be formed integrally with the tube 510a on an outer peripheral surface of the circular tube 510a and may be implemented in a structure in which a plurality of fins are spaced apart from each other in an extending direction of the tube 510a. That is, the first outdoor air-cooling type heat exchanger 500a may have a structure in which a plurality of tubes 510a penetrate through each fin 520a. Additionally, as another example, as illustrated in FIG. 3, the first outdoor air-cooling type heat exchanger 500b may include a tube 510b through which refrigerant flows and a fin 520b disposed on the tube 510b. Here, the tube 510b may be in a flat shape, and the fins 520b may be formed integrally with the tube 510b on an outer peripheral surface of the flat tube 510b and may be implemented in a structure in which a plurality of fins are spaced apart from each other in an extending direction of the tube 510b. That is, the first outdoor air-cooling type heat exchanger 500b may have a structure in which a plurality of tubes 510b penetrate through each fin 520b. The structure of the first outdoor air-cooling type heat exchangers 500a and 500b illustrated in FIGS. 2 and 3 may allow condensate to flow down quickly when the condensate forms, so that heat transfer between outdoor air and the first outdoor air-cooling type heat exchangers 500a and 500b may be smoothly achieved, thereby realizing quick defrosting. However, the first outdoor heat exchanger 500 of the present invention is not limited to this example, and may be formed of various types and forms of heat exchangers as needed.

In another embodiment, as illustrated in FIG. 4, the first outdoor heat exchanger 500c may include a flat tube 510c in which refrigerant flow paths are formed and connected to each other or spaced apart from each other in a zigzag shape with a space therebetween, and a pin 520c disposed in a space of the flat tube 510c. In another embodiment, as illustrated in FIG. 5, the first outdoor heat exchanger 500d may include a plurality of flat tubes 510d in which refrigerant flow paths are formed and spaced apart from each other with a space therebetween, and a pin 520d disposed in the space between the plurality of flat tubes 510c. Here, a plurality of partition walls 511d spaced apart from each other may be formed inside the flat tube 510d so that refrigerant flow paths having a plurality of micro channels through which the refrigerant flows may be formed.

In order for the second outdoor evaporative heat exchanger 600 to operate as an evaporative condenser in the cooling mode, a water injection module 610 including a spray portion supplying cooling water toward the second outdoor evaporative heat exchanger 600 may be disposed in an upper side or one side of the second outdoor evaporative heat exchanger 600, and a recovery module (not illustrated) including cooling water supplied through the water injection module 610 may be further disposed in a lower side of the second outdoor evaporative heat exchanger 600. Meanwhile, when the second outdoor evaporative heat exchanger 600 operates as an evaporator in the heating mode, the second an evaporation operation is performed in an air cooling manner by the second outdoor evaporative heat exchanger 600 without water injection from the water injection module 610. The second outdoor evaporative heat exchanger 600 may have a structure including a fin preventing water from flowing down.

In this case, as illustrated in FIG. 6, the flow path switching valve 700 may switch the flow direction of the refrigerant in the circulation flow path 100 so that in the heating mode, the refrigerant is evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500. In other words, in the heating mode, the flow direction of the refrigerant may be switched so that the refrigerant may be circulated by the flow path switching valve 700 on the circulation flow path 100, in the order of the compressor 300, the indoor heat exchanger 200, the expansion valve 400, the second outdoor evaporative heat exchanger 600, the first outdoor heat exchanger 500, and the gas-liquid separator 800.

According to this configuration, the refrigerant passing through the indoor heat exchanger 200 operating as a condenser in the heating mode may lead to frost formation phenomenon in which condensate forms in a process of passing through the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500, each of which act as an evaporator, but by allowing the refrigerant to pass through the second outdoor evaporative heat exchanger 600 first so that in the second outdoor evaporative heat exchanger 600, the refrigerant pressure and refrigerant temperature are higher than those in the first outdoor heat exchanger 500, a relatively small amount of condensate is generated, and accordingly, it may be possible to ensure sufficient contact between outdoor air and the second outdoor evaporative heat exchanger 600, and it may be possible to secure heating performance by inducing an occurrence of a large amount of condensate in a process in which the refrigerant whose refrigerant pressure and refrigerant temperature are relatively lowered after passing through the second outdoor evaporative heat exchanger 600 passes through the first outdoor heat exchanger 500. Specifically, when the first outdoor heat exchanger 500 is comprised of, for example, first outdoor air-cooling type heat exchangers 500a, 500b, 500c and 500d as illustrated in FIG. 2 or 3, condensate may be allowed to flow down quickly when the condensate forms, so that heat transfer between outdoor air and the first outdoor air-cooling type heat exchangers 500a, 500b, 500c and 500d may be smoothly achieved, thereby enabling quick defrosting. In other words, the condensate may flow quickly from the first outdoor air-cooling type heat exchangers 500a, 500b, 500c and 500d in which frost formation frequently occurs during defrosting and then the defrosting operation may be advanced, thereby securing a normal operation in the heating mode.

Furthermore, as illustrated in FIG. 7, the flow path switching valve 700 may switch the flow direction of the refrigerant in the circulation flow path 100 so that in the cooling mode, the refrigerant is condensed while flowing in the order of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600. In other words, in the cooling mode, the flow direction of the refrigerant may be switched so that the refrigerant may be circulated by the flow path switching valve 700 on the circulation flow path 100 in the order of the compressor 300, the first outdoor heat exchanger 500, the second outdoor evaporative heat exchanger 600, the expansion valve 400, the indoor heat exchanger 200, and the gas-liquid separator 800.

According to this configuration, in the cooling mode, the refrigerant dissipating heat and condensing while passing through the first outdoor heat exchanger 500 operating as a condenser may inject cooling water into the second outdoor evaporative heat exchanger 600 operating as an evaporative condenser, through the water injection module 610, thereby improving overall cooling performance.

Meanwhile, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed adjacently to each other. In this case, one outdoor fan F2 disposed between the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be included. Accordingly, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may share one outdoor fan F2, thereby compacting a structure of the heat pump 10 and reducing manufacturing costs.

Furthermore, at least the second outdoor evaporative heat exchanger 600, among the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, may be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100. As an example, only the second outdoor evaporative heat exchanger 600 may be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100, so that water may be injected using the water pouring module 610 over a sufficient contact area of the second outdoor evaporative heat exchanger 600, thereby significantly increasing heat exchange efficiency. However, the present disclosure is not limited thereto, and if necessary, the first outdoor heat exchanger 500 may also be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100. Specifically, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed to be inclined at a certain angle in a direction facing each other from the vertical direction on the circulation flow path 100. In other words, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed to be inclined toward the outdoor fan F2 at a certain angle from the vertical direction on the circulation flow path 100. According to this arrangement structure, heat exchange between the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 and outdoor air may be performed more smoothly by one outdoor fan F2, thereby further improving cooling performance. In this case, the water injection module 610 may be disposed on an outlet side of the second outdoor evaporative heat exchanger 600 in the flow direction of the refrigerant in the cooling mode. That is, the water injection module 610 may be disposed on the other side of the second outdoor evaporative heat exchanger 600, which is opposite to one side facing the outdoor fan F2. Accordingly, the cooling performance of the second outdoor evaporative heat exchanger 600 may be improved, a water injection amount of the water injection module 610 may be reduced, and stable operation may be secured.

Meanwhile, according to another embodiment of the present invention, a control method of the heat pump 10 having the configuration descried above is provided. Here, the heat pump 10 may include a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 arranged in series on a circulation flow path 100 in which a flow direction of refrigerant is switched depending on a cooling mode or a heating mode. Here, the first outdoor heat exchanger 500 may be the first outdoor air-cooling type heat exchangers 500a, 500b, 500c 500d described above, but is not limited thereof, and may be implemented with other heat exchangers as needed. Specifically, as illustrated in FIG. 1, the heat pump 10 may include a circulating flow path 100, a compressor 300 configured to compress the refrigerant into a high-temperature and high-pressure gaseous refrigerant, an indoor heat exchanger 200 configured to heat indoor air while allowing a refrigerant passing through the compressor 300 to exchange heat with the indoor air and to be condensed into a medium-temperature and high-pressure liquid refrigerant and an indoor fan F1 blowing the indoor air toward the indoor heat exchanger 200. Indoor fan F1, an expansion valve 400 configured to decompress a refrigerant passing through the indoor heat exchanger 200 into a low-temperature and low-pressure refrigerant, a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 configured to allow the refrigerant passing through the expansion valve 400 to exchange heat with outdoor air and to evaporate into a low-temperature and low-pressure gaseous refrigerant, an outdoor fan F2 blowing outdoor air toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, a flow path switching valve 700 configured to switch the flow direction of the refrigerant in the circulation flow path 100, a gas-liquid separator 800 disposed on an upstream side of the compressor 300, and a water injection module 610 configured to supply cooling water toward the second outdoor evaporative heat exchanger 600.

Here, the configurations of the circulation flow path 100, the indoor heat exchanger 200, the indoor fan F1, the compressor 300, the expansion valve 400, the first outdoor heat exchanger 500, and the second outdoor evaporative heat exchanger 600, the flow path conversion valve 700, the gas-liquid separator 800, and the water injection module 610 have been described above, and thus, to avoid duplication, detailed descriptions thereof will be omitted.

A control method of the heat pump 10 according to another embodiment of the present invention may control the refrigerant to be evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500 in the heating mode. Specifically, in the heating mode, the refrigerant may be controlled to be circulated in the order of the compressor 300, the indoor heat exchanger 200, the expansion valve 400, the second outdoor evaporative heat exchanger 600, the first outdoor heat exchanger 500, the gas-liquid separator 800 on the circulation flow path 100.

Here, the second outdoor evaporative heat exchanger 600 may be controlled to operate as a condenser while injecting water in the cooling mode, and may be controlled to operate as an evaporator without water injection in the heating mode.

According to the control method of the heat pump 10, in a process in which the refrigerant passing through the indoor heat exchanger 200 operating as a condenser in the heating mode passes through the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500 acting as evaporators, respectively, the refrigerant may be allowed to first pass through the second outdoor evaporative heat exchanger 600, so that in the second outdoor evaporative heat exchanger 600, the refrigerant pressure and refrigerant temperature are higher than those in the first outdoor heat exchanger 500 and a relatively small amount of condensate is generated, and accordingly, it may be possible to ensure sufficient contact between outdoor air and the second outdoor evaporative heat exchanger 600, and in a process in which the refrigerant passing through the second outdoor evaporative heat exchanger 600 passes through the first outdoor heat exchanger 500, it may be possible to secure heating performance by inducing the occurrence of a large amount of condensate. Specifically, the condensate may flow rapidly from the first outdoor heat exchanger 500 in which a large amount of frost formation occurs during defrosting, and after the defrosting operation is performed, it may be possible to ensure a normal operation in the heating mode.

Furthermore, the control method of the heat pump 10 may control the refrigerant to condense while flowing in the order of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 in the cooling mode. Specifically, in the cooling mode, the refrigerant may be controlled to flow in the order of the compressor 300, the first outdoor heat exchanger 500, the second outdoor evaporative heat exchanger 600, the expansion valve 400, the indoor heat exchanger 200, and the gas-liquid separator 800 on the circulation flow path 100. Accordingly, the refrigerant dissipating heat and condensing while passing through the first outdoor heat exchanger 500 operating as a condenser in the cooling mode may improve overall cooling performance by injecting cooling water into the second outdoor evaporative heat exchanger 600 operating as an evaporative condenser through the water injection module 610.

The first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may share one outdoor fan F2, thereby compacting the structure of the heat pump 10 and reducing manufacturing costs.

Accordingly, according to the heat pump 10 and the control method thereof according to the embodiment of the present invention, in the heating mode, the refrigerant may be allowed to flow in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500 so that frost formation of the condensate is performed mainly in the first outdoor heat exchanger 500, and accordingly, the evaporation efficiency of the refrigerant in the second outdoor evaporative heat exchanger 600 may be secured to improve the heating efficiency, and a quick defrosting operation of the first outdoor heat exchanger 500 may be performed. Additionally, in the cooling mode, the refrigerant may be allowed to flow in the order of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, so that the refrigerant may be condensed more efficiently through water injection in the second outdoor evaporative heat exchanger 600, thereby improving cooling efficiency effectively.